The possession of contraband items in prisons is widely recognised as a major risk to safety, either of the inmates, the prison staff or to persons outside of the prison. In the context of this application contraband is defined as any item which the inmate should not have in their possession and which may be used to cause harm or place a person at risk. Contraband includes knives, shanks, guns and other weapons, many of which contain metal or magnetic parts. Cell phones are considered to be contraband and to be dangerous because the can be used by inmates to arrange violent acts inside or outside of the prison, or used to conduct other criminal activities.
Archway metal detectors, AMDs, are commonly used in prisons. They require permanent installation at locations where the environment is conducive to their operation. Their main limitation is that they are permanently installed. Also, AMDs cannot be used next to large amounts of metal which severely limits where they can be installed within the metal-rich prison environment.
Hand held metal detectors, often called hand wands, have widespread use in prisons. They are inexpensive, highly portable, and can be carried into cell blocks by prison staff and used to search inmates, bedding, laundry etc. Their main drawback is their limited range. Because of this they are ineffective for internally carried phones.